In general, industrial rubber belts are roughly classified into transmission belts for transmitting power and conveyer belts for conveying articles. Available rubber raw materials include natural rubber, polybutadiene rubber, styrene-butadiene rubber, ethylenepropylenediene rubber, chloroprene rubber, chloro-sulfonated polyethylene rubber, nitrile rubber, and hydrogenated nitrile rubber.
A rubber composition for use in rubber belts is required to have large tensile strength, appropriate hardness, flexibility, elasticity, good flexibility, and a large impact resistance, and is further desired to achieve energy saving and light weight. For the purpose of satisfying these requirements, the use of an inorganic reinforcer or short fibers for reinforcement is proposed. An example of the reinforcement with short fibers is disclosed in Patent Document 1 as a rubber composition for conveyer belts. The rubber composition comprises a natural rubber and a butadiene rubber containing a crystalline syndiotactic-1,2-polybutadiene resin (also referred to as a vinyl-cis-polybutadiene rubber). The natural rubber and the butadiene rubber are compounded to retain fundamental properties of matter such as high tensile strength and wearing resistance and reduce power consumption when used in a conveyer belt.
Patent Document 1: JP 2004-346220A